Stable solutions of dihydroxy-diamino-arsenobenzene and its derivatives



Patented Mar. 24, 1936 UNITED STATES PATENT OFFICE STAB LE SOLUTIONS OFDIHYDROXY-DIAM- INO-QBSENOBENZENE AND ITS DERIVA- Franz Elger, Basel,Switzerland, assignor to Hoflmann-La tion of New Jersey.

Rochelna, Nutley, N. J., a. corpora- No Drawing. Application June15,1935, Serial- No. 26,828. In Switzerland July 6, 1934 7 Claims. (01.167-69) Solutions of diliydroxy-dialmino-arsenobenzene and itsderivatives are subject to readyand rapid decomposition which rendersthem unsuitable for therapeutic use. The decomposi- 5 tion is 'dueprobably to an oxidizing process. It

has now.'been found that the oxidation and sub- J sequent decompositionof the said solutions may be prevented by adding ascorbic acid or saltsof ascorbic acid. 10 Example 1 6 parts by weight ofdlhydroxy-diamino-arsenobenzene-sodium-methylene-sulphonate aredissolved in a solution of 3 parts by weight of ascorbic acid in 60-parts by volume of water while adding enough sodiumghydroxide solutionto bring the pH to 6.5. The 10% solution ofdihydroxy-cliamino-arsenobenzcne-sodium-methylene-sulphonate thusobtained is of a clear light 20 yellow colour and is not decomposed whenleft to stand for some considerable time unprotected from the. air,whereas a similar solution, to which noiascorbicaacid has; been added,quickly turns dark brown. f

- Example 2.

4.66 parts by weight or dihydroxy-diamino-,arsenobenzene-sodium-methylene-sulphonate are mixed with 4 parts byweight of sodium ascorbate.

. 80 The powder thus obtained yields neutral aqueous solutions, whichare stable.

I claim: 1. Stable solutions of dihydroxy-diamino-arsenobenzene and its.derivatives, containing ascorbic acid in an amount suflicient tostabilize the solution. V 5

2. Stable solutions of dihydroxy-diamino-arsenobenzene and itsderivatives, containing salts of ascorbic acid in an amount suflicientto stabilize the solution.

3. Stable solutions of dihydroiry-diamino-arl0 pound selected from thegroup consisting of ascorbic acid and the salts of ascorbic acid in anamount suflicient to stabilize the solution. 30

FRANZ. ELGER.

